1. Field of the Invention
The present invention relates to an optical waveguide device which adds an optical fiber guide and an optical element placing portion for mounting an optical fiber, a light emitting element, a light receiving element, or the like and light modulating function to an optical waveguide for transmitting light in a core, a manufacturing method of the optical waveguide device, and an optical communication apparatus which uses the optical waveguide device.
2. Description of the Background Art
In a joint portion or an end portion of the optical fiber cable used for optical communication, the optical waveguide device is used in order to connect the optical fiber cable to other optical fiber cable, the light emitting element, or the light receiving element. In recent years, utilization of optical communication that can transmit large-capacity data at high speed has progressed. Thus, the manufacturing of an optical waveguide device that is inexpensive and suitable for mass production is desired.
FIG. 1 is a schematically perspective view of an optical waveguide device 1 which is conventionally used. As shown in FIG. 2, the optical waveguide device 1 includes an optical waveguide 6 and a supporting substrate 7. The optical waveguide device 1 can be used in such a manner that the optical waveguide 6 is put on an optical waveguide placing portion 12 of the supporting substrate 7, and a core 4 of the optical waveguide is connected to the optical fiber, a light emitting element 8, light receiving element 10, or the like.
The optical waveguide 6 includes a substrate 2, the core 4 for transmitting a light therein, a lower cladding layer 3 and an upper cladding layer 5 which surround the core 4, and a filter 13d. The core 4, the lower cladding layer 3, and the upper cladding layer 5 are made of a substance, such as resin or glass, which has relatively large refractive index. So that the light is trapped in the core 4 and propagated, the refractive index of the core 4 need be large compared with the refractive indices of the lower cladding layer 3 and the upper cladding layer 5. The filter 13d is the optical element having characteristics which transmit the light having a specific wavelength and reflect the light having the wavelengths except the specific wavelength. The filter 13d is used by placing it in a filter placing groove 13c which is formed in the optical waveguide 6 so that the core 4 is divided into a core 4a and cores 4b and 4c. 
An optical fiber guide 9 for positioning and placing the optical fiber, which has a V-shaped groove in cross section, and an optical fiber placing portion 12 for putting the optical waveguide 6 on it are formed on the supporting substrate 7 formed by etching a silicon substrate 11. On the supporting substrate 7, the light emitting element 8 such as a laser diode (LD) or a light emitting diode (LED), the light receiving element, and the like 10 are placed while an end face of the core 4 is aligned with an optical axis of the transmitting light. A lead and wire bonding pads 13a and 13b for applying electric power to the light emitting element 8 and the light receiving element 10 is formed on the supporting substrate 7.
In the manufacturing of the optical waveguide device 1 in the conventional art, the optical waveguide 6 and the supporting substrate 7 were produced separately, and the optical waveguide 6 and the supporting substrate 7 were bonded one by one with the bonding resin to produce the optical waveguide device 1. Accordingly, a manufacturing process became complicated, it took much time and cost for the manufacturing process, and the mass production could not be efficiently performed. Further, since the individual optical waveguide 6 and supporting substrate 7 are minute components, it took much time and cost to precisely align the optical waveguide 6 and supporting substrate 7 to assemble the optical waveguide device 1, and it was difficult to improve net productivity.
On the other hand, a plurality of optical waveguides 6 and a plurality of supporting substrates 7 are formed on wafers or mother boards respectively, the two wafers or the two mother boards are bonded together, and then the bonded body is divided into the individual optical waveguide devices. As a result, the productivity is improved. However, in the optical waveguide device 1 in which the pad portion for mounting the light emitting element 8 or the light receiving element 10 and the optical fiber guide 9 are provided in the supporting substrate 7, since the light emitting element and the light receiving element are finally mounted on the pad portion and the optical fiber need be fixed to the optical fiber guide 9, it is necessary to expose the pad portion and the optical fiber guide 9. Accordingly, in the method in which the plurality of optical waveguides 6 and the plurality of supporting substrates 7 are formed on the wafer or the mother board respectively and the both wafers or the both the mother boards are bonded over the surfaces, it is difficult to expose the optical fiber guide 9 or the pad portion, and possibility of the manufacturing method was low in the optical waveguide device having the optical fiber guide 9 or the pad portion.